Location of gingival margin apical to the cementoenamel junction or implant connection. Marginal tissue recessions were classified by Miller in four classes according to predictability of root coverage. (Class I): Recession does not extend to the mucogingival junction and there is no tissue loss in the interproximal area. (Class II): Recession extends to or beyond the mucogingival junction. There is no periodontal loss in the interproximal area. (Class III): Recession extends to or beyond the mucogingival junction. Bone or soft tissue loss is present in the interdental area, or there is malpositioning of the teeth which prevents total root coverage. (Class IV): Recession extends to or beyond the mucogingival junction. The bone or soft tissue loss in the interdental area and/or malpositioning of teeth is so severe that root coverage cannot be anticipated.
Migration of the gingiva to a point apical to the cementoenamel junction.
Apical migration of the gingiva resulting from faulty toothbrushing technique, tooth malposition, friction from soft tissues, gingival inflammation, and high frenum attachment. The incidence of recession may result in sensitivity, increased susceptibility to caries, and difficulty maintaining clean teeth.